1. Field of the Invention
This invention relates to monitoring the radio transmissions of railway End of Train devices and Head of Train devices, and more particularly, monitoring such transmissions for verifying communication links therebetween, identifying particular devices, and tracking the locations and routing the destinations of such devices.
2. Discussion of Related Art
Individual railway vehicles commonly have a brake line that runs from one end of the vehicle to the other. The process of assembling a train includes coupling these individual brake lines together to form a continuous brake line running from one end of the train to the other. Air pressure introduced into this brake line activates the brakes on each of the individual vehicles. Air pressure within the brake line above a threshold pressure causes the brakes on a vehicle to release. When pressure in the brake line falls below a threshold value, the brakes default into an applied state.
To insure the integrity of the brake line and proper operation of the brakes, the air pressure in the brake line is monitored at both the forward and at the rear end of the train. A Head of Train (HOT) device mounted on a locomotive monitors the brake line pressure at the front end of the train. An End of Train (EOT) device that is removably mounted near the rear coupling of the last car of the train monitors the brake line pressure at the rear end of the train.
The EOT device is equipped with a valve that is connected to an end of the brake line. The valve, when opened, releases compressed air from the brake line, thus permitting the brakes of each car to assume the default braking state. The HOT displays EOT status information. The HOT also provides control for an emergency valve in the EOT device.
The HOT unit communicates with the EOT unit, typically over Ultra-High Frequency (UHF) or Very-High Frequency (VHF) radio channels, as part of an end of train monitoring system. Radio tranceivers in the HOT and EOT devices are adapted to transmit operational messages to the other device. These messages allow for testing of the devices, control of the EOT device by the HOT device, and the transmission of status information from the EOT device to the HOT. Operating personnel may review or record the information.
Each EOT device is provided with a unique identification number that is fixed at the time of its manufacture. The HOT device typically includes a microprocessor and memory along with a user interface through which an operator stationed at the HOT device can enter, for example, the identification code for a particular EOT device mounted at the far end of the same train.
Once a HOT device has been programmed with the EOT identification number and communication between the HOT and designated EOT have been established, the HOT communicates exclusively with that EOT device. Communication between the HOT and the EOT devices take place on an ongoing basis during normal operation of the train.
To establish communication between the HOT and EOT devices, a link must be established therebetween. This link is initialized by a multi-stage communication xe2x80x9chandshakexe2x80x9d designed to assure reliable and exclusive communication. The success of this handshake or xe2x80x9clinkxe2x80x9d is critically important to the safe operation of the train. Accordingly, monitoring the linking process while assembling a train would be very useful.
Most railroad organizations regularly rely on EOT devices for the safety of their trains. The EOT devices are attached to trains that typically travel across the tracks of two or more different railroad companies. Normally, when a train carrying the EOT device of one company reaches a destination within the rail network of another company, the EOT device is removed and replaced by an EOT belonging to the company of the network being traversed. The removed EOT then is returned to the owner of the EOT. However, operational and scheduling constraints, make it impractical to remove and replace the EOT at the first stop within a new network. Consequently, EOT devices regularly are loaned or rented between railroad organizations. The rental fees, although not unduly high, can grow substantially when an EOT device becomes xe2x80x9clostxe2x80x9d or cannot readily be returned to its owner. Likewise, failing to properly record the return of EOT devices can result in an EOT being deemed xe2x80x9clostxe2x80x9d with like consequences in terms of accumulated rental fees. Accordingly, it would be beneficial to have a system that could locate EOT devices and automatically provide a message including return instructions including a destination address, to railway personnel at each successive stop made by the EOT bearing train.
Various HOT and EOT communication devices have been proposed. For example, a known automated initial terminal testing system tests the air pressure and leakage of brake lines and the operation of the brakes of railroad trains, and discloses the use of a central control console to monitor both the HOT and EOT devices on each track in the yard and remotely control the HOT devices. Another device, positioned at the wayside of a railway system, detects and transmits information about defects to be transmitted from the wayside to the train for display in the locomotive. The existing user interface of a modified HOT device is proposed as the means for display of information thus transmitted. A known mobile communications package is capable of responding to Query for Health reports with data for keeping an inventory of on-board equipment.
None of the foregoing disclose the various useful and novel aspects of the present invention, nor would they serve to meet the objectives of this invention disclosed within.
In view of the above, the invention provides for ready monitoring and troubleshooting of the linking process, by independently accessing the HOT-EOT communications channel. The invention also ensures the return of EOT devices to their owners.
The invention also provides for a network and database to provide EOT devices with return messages to ensure timely return of the EOT devices to their rightful owners.
The invention is a method and a system for monitoring the ongoing communications between HOT and EOT devices, and sending radio signal messages that may be received and operated on by an unmodified EOT or HOT device, for routing EOT devices back to their owners.
The invention monitors the linking procedure executed by the HOT and EOT devices for establishing radio communications therebetween, and to confirm whether the linking procedure is successful or unsuccessful.
The present invention troubleshoots suspect communication links to ascertain the device responsible for a perceived link failure.
The invention monitors the broadcasts of the EOT device and records the identification and status information contained therein.
The invention identifies the presence of foreign EOT devices on trains operating within a rail system, notifies appropriate railway personnel of the need to replace the foreign EOT device with a company EOT device, and provides railway personnel with address and procedural information related to the foreign EOT device.
The invention locates within a foreign railway systems non-company EOT devices, indicated by independent records to be on loan to the company.
The invention identifies company EOT devices operating on foreign railway systems to assume their ultimate return.
These and other advantages of the invention will become apparent to those of skill in the art from the following drawings and description which illustrate some non-limiting embodiments of the invention.